one of the rarest of the non-Hodgkin's lymphomas

Seattle Genetics has initiated a Phase I clinical trial assessing SGN-CD70A for CD70-positive relapsed or refractory non-Hodgkin lymphoma (NHL) and metastatic renal cell carcinoma (RCC).

SGN-CD70A is a new antibody-drug conjugate (ADC) targeted to CD70 using Seattle’s new ADC technology.

The open-label, multicentre, dose-escalation Phase I trial is designed to assess the safety and anti-tumour activity of SGN-CD70A.

The primary endpoints of the trial are to estimate the maximum tolerated dose and assess the safety of SGN-CD70A.

Furthermore, the trial will evaluate the anti-tumour activity and pharmacokinetics in patients with CD70-positive metastatic RCC or relapsed or refractory NHL, including mantle cell lymphoma and diffuse large B-cell lymphoma.

Around 95 patients at multiple centres in the US will be enrolled in the trial, which is designed to assess SGN-CD70A administered every three weeks.

Seattle Genetics R&D chief medical officer and executive vice-president Jonathan Drachman said: "CD70 is a very promising ADC antigen, which is highly expressed in both NHL and RCC, and has minimal expression in healthy tissues.

"We are building on the single-agent activity we observed with our former SGN-75 candidate and have designed SGN-CD70A with a goal to have enhanced activity by utilising our next-generation ADC technology.

"The primary endpoints of the trial are to estimate the maximum tolerated dose and assess the safety of SGN-CD70A."

"Our preclinical data demonstrate that this novel ADC is extremely potent in RCC and NHL models, and we are enthusiastic about commencing a clinical trial of SGN-CD70A in patients with a clear need for new therapeutic options."

Seattle Genetics had previously observed single-agent activity including objective responses in a Phase I clinical trial with an initial CD70-targeted ADC called SGN-75, but did not observe enough activity to support further clinical development.

The company developed a next-generation anti-CD70 ADC using new technology that includes a highly potent cytotoxic agent, called a pyrrolobenzodiazepine (PBD) dimer, stably linked to a CD70-directed antibody via proprietary site-specific conjugation technology.

Image: Micrograph of mantle cell lymphoma, a type of non-Hodgkin lymphoma. Photo: courtesy of Nephron.